Power transmission



Dec. 9, 1941.

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F. T. HARRINGTON ETAL "POWER TRANSMISS ION Filed Dec. 31, 1938 FIG.

2 Sheets-Sheet l 7 i'f'o 'llllllllllllllll B. GARD|NER X M ATTORNEY Dec. 9,

POWER TRANSMISSIQN Filed Dec. 31, 193 8 ZSheefs-Sheet 2" INVENTORS FERRIS T. RRINGTON a. BYDUNCAN GARDINER W Z, M ATTORNEY ,T.HARR1NGTON ETAL 2,265,430

Patented Dec. 9, 1 941 DFFICE rowan rmnsmssron Ferri T. Harrington and Duncan B. Gardiner,

Detroit, Mich., rated, Detroit,

assi'gnors to Vickers Incorpo- Mich a corporation of Michigan Application December 31, 1938, Seriai No. 248,766

9Claims.

This invention relates to power transmissions, particularly to those of thetype comprising two or more fluid pressure energy translating devices one of which may function as a as a fluid motor.

The invention is particularly 'concerned with power transmission systems for operating clutches, brakes, and the like requiring greater effort than can be conveniently applied manually and wherein it is desirable to retain a feel" in the operating handle which is similar to that of a direct manually operated clutch or brake.

In road and excavating machinery it is common to operate various 'shiftable parts of the mechanism which require large forces to move them by means of hydraulic cylinders supplied with power from a hydraulic pump. Frequently it is also desirable to operate one or-more clutches or brakes also by hydraulic power, and for most satisfactory control of the device. it is necessary that the operator be able to determine by the feel of the control handle the extent ofengagement of the clutch or brake. to provide for rapid positive disengagingmovement of the clutch or brake by hydraulic power.

As more particularly disclosed in the applica- ,tion of L. Raymond Twyman, Serial No. 202,294, filed April 15, 1938, for also customary to provide a bank of control valves It is also desirable for controlling the various cylinders of a particular group or a machine which valve bank is made up of unit sections, one section for each cylinder, which sections are adapted to be mounted in side-. by-side relation in such numbers and combinations as may be required in It is an object of the present invention to provide an improved power transmission system for operating a clutch, brake, or the like wherein the clutch or brake may be applied to a varying extent under complete operator control.

It is also an object to provide a system of the character described wherein the clutch or brake pump and another Multiple valve bank, it is any given installation.

may be rapidly released by power, utilizing the I full capacity of the hydraulic system.

It is a further object to provide an improved -clutcl1 or brake controlling valve for providing the above-described results and which is adapted to be incorporated in a multiple valve bank with any desired number or combination of other 'con-' trol valves similar to those described in the application above-mentioned.

Further objects and advantages of the present invention will be apparent from. the following description, reference being had to the accompanying drawings wherein a preferred form the present inventionis clearly shown.

In the drawings: Figure ,1 is a diagrammatic view of a power transmission system embodying a preferred form of the present invention.

Figure 2 be longitudinal cross-section of a clutch or brake controlling valve forming a part of the circuit disclosed in Figure 1.

Figure 3 is a fragmentary view of the v control valve disclosed in Figure 2.

Figure 4 is a cross section through the valve bank disclosed in Figure 1. V Figure 5 is a cross section on line 5-5 .of Figure 4.

ure 4.

Referring now to Figure 1, there is showna pump In, which may be of the fixed displacement type and continuously driven by a prime mover such as an electric motor I 2 to withdraw fluid from a tank l4 through a suction conduit l6 and deliver the same to a" delivery conduit l8. The conduit It leads to a port 2! formed in the end plate 22 which forms part ofa valve bank generally designated as 24. .,The latter in the example disclosed is made up of three valves 28, 28 and 3| and has a second end plate 32' at its right-hand end having a port 34 which is connected to the tank l4 by a conduit 36.

Each of the valves in the bank has a pair ofv cylinder ports designated as 38, 40, 42, 44, 4t and 48. The ports 38 and 40 connect to the rod and head ends respectively of a cylinder 50 by conduits 52 and 54. Ports 42 and 44 connect to the head and rod ends respectively of a cylinder 58 by conduits 58 and 60. Ports 4i and 48 connect with the head and rod ends respectively of a cylinder 62 by conduits i4 and 68.

The cylinder 50 hasa piston 68 the rod "of which may be connected to a gear box 12 for shifting thereof between a forward and reverse connection.v The cylinder 56 has a piston 12 therein the rod 14 ofwhich may be connected to the operatinglever 16 of a clutch l8. Cylinder 62' has a piston therein the rod I2 01' which may be connected to an operating lever 84 for a brake 86.

, Each of the valves 28, 28 and 30 is provided with an operating handle 88,. fill and 82 for controlling the stem or spool of the valves.

As shown in Figure 3, lever 80 is pivotally mounted at one end to a link 94 which is pivoted to the body of the valve, and at its mid portion is pivotally 'mounted to the valve operating stem.

Figure 6 is a cross' sectionon lineH of Fig longitudinal bore or recess in which the movable se forms no part of the present invention.

Briefly the valve is provided with a transverse pressure passageway 66 and transverse tank passageways 68 and I00. The cylinder ports 38,

and 40 connect with annular'chambe'rs I02 and I04 and are adapted to be selectively placed in communication, either one with the pressure passageway 66 and the other with one of the tank passageways 68 or I 'or vice versa. The valve also has an unloading passageway formed in two parts I08 and I08 which are normally in cylinder port 42 and chamber I36by means of alongitudinal slots I46 (see Figure 2) in which a pin I46 is received to provide a lost motion connection between the plunger I40 and the spool II4.

At the lower nd of the spool there is provided in an end cap I50 a cylinder chamber I52 in which is slidably mounted a small" piston I54. The latter, when raised, is adapted to abut the lower end'of the spool II4 for lifting the same. The cylinder I52! is in communication with the drilled passageway I56 shown in Figure 2.

communication when the spool I I0 is in the central position as illustrated. Whenever the spool is shifted either upwardly or downwardly to connectthe cylinder'ports to the pressure and tank passageways, theunloading passageway is blocked by the spool IIO. Suitable spring centering means at H2 is provided for normally holding the valve spool in its center or neutral Q way in valve 26. The spool H4 is provided with lands I26, I26, I30, and I34 for controlling the various passageways. The cylinder ports 42 and 44 communicate with annular chambers I36 and I36 respectively.

The lands I and I34 are so arranged that in the center or neutral position shown both chambers I36 and I36 are in communication tively. When the spool I I4 is moved upwardly chamber I36 is blocked from the tank passageway I2I and placed in communication with the pressure passageway- II6. 'At the same time chamber I36 remains in communication with the tank passageway I20. If the spool II 4 be moved downwardly from the position shown chamber with the tank passageways I20 and I2I respec-' I36 is blocked from communication with the tank passageway I20 and placed in communication with the pressure passageway II8. The chamber I38 remains in communication with the tank passageway- I2I. when the valve spool is moved either upwardly or downwardly the unloading passageway is blocked by one or the other of the iands l26 and I28. v

For operating the spool II4 there is provided at the upper end of the valve body a plunger I40 slidably mounted in an end cap I42 and receiving the upper end of a spring I 44. Thelower endot the spring abuts the top end of the spool H4. The plunger I40 is also provided with a p irjot It will be seen. that whenever the'plunger I40 is lifted from the position shown, the end of the slots I46 being in engagement with the pin I46, the spool II4 will be directly lifted to the same extent that theplunger I40 is lifted; the spring centering means II6 yieldably resisting such movement. It the plunger I40 be pushed downwardly from the; position shown, the spring I44 will be compressed without necessarily causing the spool II4 to follow the movements of the plunger I40. The spool II4 will move down initially, however, until chamber I36 is cracked open to the pressure passageway II6, atwhich time pressure oil. admitted to the chamber I36 will also be admitted to the cylinder I52 through the passageway I 56. The piston I54 will thus exert an upward pressure on the spool II4 causing'the valve as a whole to act as a pressure reducing valve and maintain in the chamber I36 a pressure which isdependent upon the degree of compression of the spring I44.

The construction of the end plates 22 and 32 may be similar to that disclosed in the copending application above referred to. The port 20 of the plate 22 communicates with a longitudinal passageway I56 which has lateral extensions I60 and I62 in register with the unloading passageway I06 and with the pressure passageway 66 respectively. The longitudinal passageway I56 also communicates with a relief valve I64 the opposite side of which connects to a port I66 which registers with the tank passageway I00.

. The plate 22 is blanked at the point registering.

with the tank passageway 68. I The plate 32 is provided with a longitudinal passageway I66 having lateral extensions I10,

I12 and I14 which communicate with the unloading passageway I24, the tank passageway I2I, and the tank passageway I20 respectively. There is also provided a fourth lateral extension I16 which communicates with a seepage drain passageway I18 extending through each of the three valves 26, 28 and 30 and registering with a blank portion of the end plate 22. The end plate 32 is blanked at the point where it registers with the pressurepassageway II8.

In-operation,"with the parts in the position shown in the drawings. that is, with all valves pump at the passages I06 and I08 so that the a full pump delivery passes from port 20 through. I

passage I56, extension I 62, pasage 66, chamber I04, port 40, and conduit 54 to the head end of ing such fluid motors as may be required from cylinder 50. The piston 08 accordingly moves to the left discharging oil from the rod end of cylinder 50 through conduit 52, port 30, chamber I02, passageway I00, passage I20, extension I", passage I08, port 34,,and conduit 36 to tank. For opposite movement of the piston 50 valve spool H will, of course, be shifted downwardly which establishes the opposite connections to conduits 52 and 54.

If it is desired to engage the clutch 18, the

operating handle 90 will be depressed causing the spool II4 to move downwardly, as previously described, blocking the unloading passageways I22 and I24 and admitting pressure oil to the port 42, line 58, and head end of cylinder 56. The piston 12 accordingly moves to the right until suiilcient pressure is built up to cause the piston I54 to lift spool. II4 to the point where chamber I36 is just closed off from communication with passageway I20. It will be seen that the pressure at which this action occurs depends upon the degree of compression of the spring I44 which gives the operator the same feel. at the lever 90 as he would haveif the lever were directly connected to the clutch I8 except that the force required at the lever 90 for full engagement is only a fraction of the force required at the lever I6. The force at the lever 90, however, is proportional to that exerted at the lever 16. The engagement of the clutch may thus be controlled with great nicety in accordance with operating conditions and requirements in exactly the same manner as if the clutch were operated by hand. The additional advantage is provided, however, that the force required for operating the clutch is greatly reduced.

If it is desired to release the. clutch gradually the handle 90 may be merely permitted to move upwardly gradually to th central position thus permitting the piston I54 to lift the valve spool also be drawn into the rod end of cylinder 56 through the conduit 60 under these conditions.

If it is desired to quickly release the clutch at a greater speed than occurs under the action just described, the lever 90 may be lifted upwardly past central position to not only connect chamber I36 to tank but also connect chamber I38 to the pressure passageway 96 and to block the unloading passages I22 and I24. Under these conditions the full capacity of the pump is available for moving the piston 12 to the left under oil pressure delivered through the conduit 60.

The operation of the valve .30 for controlling brake 86 is-identical to that described in connection with the valve 28 and clutch 18 so that the action thereof will be obvious. It will be seen that the present invention provides a power transmission system in which a,

clutch or brake may be precisely controlled as to its engagement by a lever having the same feel as a directly connected clutch or brake operating lever. This result is achieved through the use of a novel control valve so constructed as to permit of assembly with other similar valves into a valve bank capable of receiving any num-' ber or combination of control valves for operatpressure oil is not required for the operation of the system. customarily such unloading means are associated with,an accumulator on the pressure line I0 together with an unloading valve responsive to the amountof oil in the accumulator or to the oil pressure therein, and which serves to unload the pump when the accumulator has been filled.

While the form of embodiment of the invention, as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A manually operable pressure controlling valve comprising a housing having a longitudinal valve member recess with transverse pressure and exhaust passageway-s and a transverse motor port opening to said recess, a shiftable valve member in said recess and having lands for controlling communication of saidmotor port with said passageways, means responsive to pressure in said motor port for shifting the valve member in a direction tending to open the motor port to the exhaust passageway, a spring tending to shift the valve member in the opposite direction, and a manually operable plunger for controlling the force of the spring, said housing having transversely aligned pairs of openings in its opposite sides, each pair communicating with one of said passages and when mounted in a valve bank adjacent similar housings being adapted to register with similarly located openings to provide continuous passageways through the bank.

2. A manually operable pressure controlling valve comprising a housing having a longitudinal valve member recess with transverse pressure andexhaust passageways, an unloading passageway and a transverse motor port opening to said recess, a shiftable valve member in said recess and having lands for controlling communication of said motor port with said passageways, means responsive to pressure in said motor port for shifting the valve member in a direction tending to open the motor port to the exhaust passageway, a spring tending to shift the valve member in the opposite direction, and a manually operable plunger for controlling the force of the spring, said valve member having means for blocking the unloading passageway when the valve is shifted to open the motor port to the pressure passageway, said housing having transversely aligned pairs of openings in its opposite sides, each pair communicating with one of said passages and when mounted in a valve bank adjacent similar housings being adapted to register with similarly located openings to provide continuous passageways through the bank.

3. A manually operable pressure controlling valvecomprising a body having a longitudinal valve member recess with pressure and exhaust passageways and motor ports opening to said recess, a shiftable valve member in said recess and having lands for controlling communication of said motor ports with said passageways, means responsive to pressure in said motor ports for shifting the valve member in a direction tending to open one motor port to the exhaust 'passag'eway and open the other motor port to the pressure passageway; aspring tending toshift the valve memberlin the opposite direction, and a manually operable plunger for controlling the force of'the spring "and having a lost-motion connection with the valve member for shifting the same past its center position in a direction to open said one motor port tothe exhaust passageway and open-the other motor port to the pressure passageway, i

A an l y op rab valve comprising abody having .a longitudinal valve member recess withv pressure and exhaust passageways and motor ports opening to said recess, a sh'iftable valve member in said recess and having lands for controlling com unication ofsaid motor ports with said passageways, means responsive to pressure in said motor ports for shifting the valve memberin a direction tending to open one motor port to the exhaust passageway and open the other motor port to the pressure a controlling pressure passageway, a spring tending to shiit the valve member in the opposite direction, a manually 'operableplunger for controlling the iorcenoi the spring and having a lost-motion connection with the valve member ior shitting th'e'same past its centerposition in a direction to open said one motor port to-the exhaust passagewa and open the other motor port to the pressure passageway, and additional spring means for normally holding the valve member in its center position. v a a 5. A manually operable pressure controlling valve for controlling the operation of a fluid motor for operating a brake, clutch or the like comprising a housing having a longitudinal valve member recess with transverse pressure and exhaust passageways and a transverse motor port opening to said recess, a shiitable valve member in said recess and having'lands for controlling communication of said motor port with said passageways, and a manually operable member iorv shifting said valve member and connected to the valve member for pressure controlled operation thereof in one direction of motor actuation and for direct mechanical operation in the opposite direction, said housing having transversely aligned pairs of openings in its opposite sides, each pair communicating with one of said passages and when mounted in a valve bank adjacent similar housings being adapted to register with similarly located openings to provide continuous passageways through the bank.

6. A manually operable pressure controlling valve for controlling the operation of a fluid motor for operating a brake, clutch or the like comprising a; housing having a longitudinal valve member recess with transverse pressure and exhaust passageways and transverse motor ports opening to said recess, a shiitable valve member in said recess and havinglands for controlling communication of said motor ports with said passageways, and a manually operable member for shifting said valve member and connected to the valve member for pressure controlled operation' thereof in one direction of motor actuation and for direct mechanical operation in the opposite-direction whereby the clutch orbrake operating motor may be controlled with feel" in said one direction and may be operated quickly at full capacity in the opposite direction, said housing having transversely aligned pairs of openings in its opposite sides, each pair communicating with one of said passages and when her in said recess and having lands for selective- 1y transposing communication of said motor ports with said passageways, and a manually operable member for shifting said valve member and connected to the valve member. for positive pressure controlled operation thereof in one direction of motor actuation and for direct mechanical operation in the opposite direction.

'8. A manually operablelpressure controlling.

valve for controlling the operation of a fluid motor for operating a brake, clutch or the like comprising a body having a longitudinal valve 7 member recess with transverse pressure and exhaust passageways and transverse motor ports opening to said recess, a shiitable valve member in said recess and having lands for controlling communication of said motor ports with said passageways, and a manually operable member for shifting said valve member and connected to the valve member for positive pressure controlled operation thereof in one direction of motor actuation and for direct mechanical operation in the opposite direction whereby the clutch or brake operating motor may be controlled with ieel in said one direction and may be operated quickly at full capacity in the opposite direction.

9.,A'manually operable pressure controlling valve for controlling the operation of a fluid motor for operating a brake, clutch or the like comprising' a body member and 'a movable member together forming a four-way valve, spring centering means for normally holding the valve in neutral position, pressure controlled means for operating the valve away from neutral in one direction, and a single manually operable control member for adjusting the pressure controlled means when moved in one direction and ,for directly and mechanically operating the valve away from neutral in the opposite direction in dependently of pressure.

FERRIS T. HARRINGTON. DUNCAN B. GARDDIER. 

